RockStarApps has put together a handy “Ajax Maps Bake-Off” which lets you see how the biggest Ajax-driven maps compare side-by-side. The page loads a Microsoft, Google, and Yahoo map side-by-side, and keeps them synchronized for easy comparison.

The performance is - understandably - a little slow to keep the three maps sync’d, but it is nice to have an apples-to-apples view of how each system handles the little details.

• I find the rendering of Microsoft’s Live Maps to be superior to either Google or Yahoo. The MS maps are more like one you’d have in your car’s glove box, with nice terrain details like the locations of streams and creeks.
• Yahoo Maps has better color contrast than Microsoft or Google, which is important if you’re using a mobile device with a small screen.
• Microsoft and Yahoo display directional information on one-way streets, a must-have that Google has omitted. (I would much rather know whether the street I’m approaching is one-way than see somebody’s cat in a nearby window.)